The effect of CNO on PR-performance is dose-dependently suppressed by a DRD1-antagonist.

(A) In seven animals cannulae were correctly placed in the nucleus accumbens (Acb). The outlined numbers represent the location of the ending of the guide cannulae, for each animal (1–8) individually. Abbreviations: AcbC = nucleus accumbens core, AcbSh = nucleus accumbens shell, CPu = caudate putamen. (B) Representative image (animal 5) of cannula placement in the Acb. The horizontal arrow indicates the ending of the cannula (C) Intra-Acb infusions of the D1-antagonist SCH22390 dose-dependently suppressed CNO-induced increases in the number of active lever presses. Data are depicted with bars representing group means+SEM, with * indicating a significant difference of i.p. CNO vs. i.p. saline of p<0.05 and & indicating a significant difference of intra-Acb SCH23390 vs. intra-Acb saline of p<0.05.